Pellicle frame, pellicle, and method for peeling pellicle

ABSTRACT

The present invention is to provide a pellicle frame in a frame shape having an upper end face on which a pellicle film is to be arranged and a lower end face to face a photomask, which is characterized by being provided with a notched part from the outer side face toward inner side face of the lower end face; a pellicle including the pellicle frame as an element; and a method for peeling a pellicle from a photomask onto which the pellicle has been attached, which is characterized by inserting a peeling jig into a notched part from a side face of a pellicle frame, and moving the peeling jig in an upper end face direction of the pellicle frame in this state to peel off the pellicle from the photomask.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation application of application Ser. No.17/948,884, filed on Sep. 20, 2022, which is a Continuation applicationof application Ser. No. 17/158,476, filed on Jan. 26, 2021 (now U.S.Pat. No. 11,480,870, issued on Oct. 25, 2022), which is a Continuationapplication of application Ser. No. 16/127,605, filed on Sep. 11, 2018(now U.S. Pat. No. 10,935,882, issued on Mar. 2, 2021), which claims thebenefit under 35 U.S.C. § 119(a) to Patent Application No. 2017-196982,filed in Japan on Oct. 10, 2017, all of which are hereby expresslyincorporated by reference into the present application.

TECHNICAL FIELD

The present invention relates to a pellicle frame to be attached onto aphotomask for lithography as a dust guard, a pellicle, and a method forpeeling a pellicle.

BACKGROUND ART

In recent years, in a design rule of a large scale integration (LSI),miniaturization to sub-quarter micron has progressed, and along with theminiaturization, the wavelength of an exposure light source has beenshortened. That is, the exposing light source has shifted from a g-line(436 nm) or i-line (365 nm) by a mercury lamp to a KrF excimer laser(248 nm), ArF excimer laser (193 nm) or the like, and further, extremeultra violet (EUV) exposure using an EUV light having a main wavelengthof 13.5 nm has been also studied.

In the semiconductor production of a LSI, a very large scale integration(VLSI) or the like, or in the production of a liquid crystal displayboard, a pattern is formed by irradiating a semiconductor wafer or anoriginal plate for liquid crystal with light, however, if dust adheresto a photomask for lithography and a reticle (hereinafter, collectivelyreferred to as an “exposure original plate”), which are to be used inthis case, this dust absorbs light or bends light, so that there hasbeen a problem that the transferred pattern is deformed or the edgebecomes coarse, further the base becomes black and dirty, and thedimension, the quality, the appearance, or the like is impaired.

These works are usually performed in a clean room, however, it is stilldifficult to keep an exposure original plate clean. Accordingly, amethod in which exposure is performed after attaching a pellicle as adust guard onto a surface of an exposure original plate is generallyadopted. In this case, foreign matters do not adhere directly onto asurface of an exposure original plate but adhere to a pellicle,therefore, if the focal point is set on a pattern of the exposureoriginal plate at the time of lithography, the foreign matters on thepellicle become irrelevant to the transfer.

As to the basic constitution of the pellicle, a pellicle film having ahigh transmittance for the light to be used for exposure is stretched onan upper end face of a pellicle frame, and further an airtight gasket isformed on a lower end face of the pellicle frame. In general, apressure-sensitive adhesive layer is used for the airtight gasket. Thepellicle film is made of nitrocellulose, cellulose acetate, afluorine-based polymer or the like, which well transmits the light (ag-line (436 nm) or i-line (365 nm) by a mercury lamp, a KrF excimerlaser (248 nm), ArF excimer laser (193 nm) or the like) to be used forexposure, however, for EUV exposure, an ultrathin silicon film or acarbon film has been studied as a pellicle film.

Although a pellicle is used by being attached onto a photomask, in acase where a pellicle film becomes heavily dirty, in a case where apellicle film is broken, or the like, it is required to peel thepellicle from the photomask. For this reason, a recess (jig hole) havinga diameter of around 1 mm is provided on an outer side face of apellicle frame in order to insert a peeling jig. For example, in thefollowing Patent Document 1, a method in which a pin arranged in apeeling jig is inserted into a jig hole and peeling is performed byusing this principle has been disclosed.

By the way, there are some restrictions on a pellicle frame for EUVexposure as a matter of convenience of an exposure device. Since thepellicle arrangement space in an EUV exposure device is small, theheight of a pellicle is required to be 2.5 mm or less. In addition,since the pellicle may be exposed to a high temperature during EUVexposure, the pellicle frame for EUV is preferably made of a materialhaving a linear expansion coefficient equal to or lower than that of thepellicle film for EUV.

The height of the pellicle for EUV is required to be 2.5 mm or less,therefore, the thickness of the pellicle frame is less than the 2.5 mm.In a case where a jig hole having a diameter of 1 mm is provided on anouter side face of such a pellicle frame, the thickness in the vicinityof the jig hole of the pellicle frame becomes thin. Therefore, there isa concern that the pellicle frame may be broken during processing of ajig hole or during peeling of a pellicle. In order to avoid the problem,it is conceivable to reduce the diameter of a jig hole, however, in thatcase, it is required to increase the number of jig holes in order toreliably perform the peeling. In this regard, the possibility of thebreakage during processing is increased, and the yield is deterioratedafter all. In particular, in a case where a brittle material such as asilicon crystal is used as a material for a pellicle frame, this problembecomes prominent.

CITATION LIST

-   Patent Document 1: JP-A 2007-298870

SUMMARY OF THE INVENTION

The present invention has been made in view of such circumstances, andan object of the present invention is to provide: a pellicle frame thatis hardly broken during the processing of a jig hole formed in apellicle frame or during the peeling of peeling a pellicle from aphotomask; a pellicle using the pellicle frame; and further a method forpeeling a pellicle.

The present inventors have found that in a pellicle frame in a frameshape, which has an upper end face on which a pellicle film is to bearranged and a lower end face to face a photomask, by providing anotched part from the outer side face toward inner side face of thelower end face, the risk of the breakage of a pellicle frame is reliablyeliminated during the processing of a jig hole formed in the pellicleframe that has been conventionally used or during the peeling of apellicle, and further, when a pellicle is peeled off from a photomaskonto which the pellicle has been attached, the pellicle can be reliablypeeled off by inserting a peeling jig into the notched part and movingthe peeling jig in an upper end face direction of the pellicle frame;and thus have completed the present invention.

Therefore, the present invention provides the following pellicle frame,pellicle, and method for peeling a pellicle.

-   -   1. A pellicle frame in a frame shape, having an upper end face        to arrange a pellicle film thereon and a lower end face to face        a photomask, and a notched part being provided from an outer        side face toward inner side face of the lower end face.    -   2. The pellicle frame according to 1, wherein the notched part        is formed from the outer side face up to the inner side face.    -   3. The pellicle frame according to 1, wherein the pellicle frame        has a thickness of less than 2.5 mm, and is made of a silicon        crystal.    -   4. A pellicle, including: the pellicle frame according to 1 as        an element.    -   5. The pellicle according to 4, wherein a mask        pressure-sensitive adhesive layer is arranged on a part other        than a notched part on a lower end face of the pellicle frame.    -   6. A method for peeling the pellicle according to 4 from a        photomask, the pellicle being attached onto the photomask, the        method including: inserting a peeling jig into a notched part        from a side face of a pellicle frame; and moving the peeling jig        in an upper end face direction of the pellicle frame in this        state to peel off the pellicle from the photomask.    -   7. The method for peeling a pellicle according to 6, wherein an        insertion part of the peeling jig has a flat plate shape        corresponding to the notched part.

Advantageous Effects of the Invention

According to the present invention, a pellicle frame that is hardlybroken during the processing of the pellicle frame or during the peelingof a pellicle, and a pellicle using the pellicle frame can be provided.In addition, in the present invention, a pellicle can be reliably peeledoff from a photomask without causing any problem of breakage or thelike.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A to 1C are schematic views showing one embodiment (Example 1) ofa pellicle frame according to the present invention, FIG. 1A is a viewas viewed from a lower end face side, FIG. 1B is a view as viewed froman outer face side of the long side, and FIG. 1C is a view as viewedfrom an outer face side of the short side;

FIGS. 2A to 2C are schematic views showing another embodiment of thepellicle frame according to the present invention, FIG. 2A is a view asviewed from a lower end face side, FIG. 2B is a view as viewed from anouter face side of the long side, and FIG. 2C is a view as viewed froman outer face side of the short side;

FIGS. 3A to 3C are schematic views showing another one embodiment(Example 2) of the pellicle frame according to the present invention,FIG. 3A is a view as viewed from a lower end face side, FIG. 3B is aview as viewed from an outer face side of the long side, and FIG. 3C isa view as viewed from an outer face side of the short side;

FIG. 4 is a schematic view as viewed from a lower end face side of apellicle with the pellicle frame of FIGS. 1A to 1C to which apressure-sensitive adhesive layer and a pellicle film are arranged;

FIG. 5 is a schematic view of one in which the pellicle of FIG. 4 isattached onto a photomask, as viewed from a Z side of FIG. 4 ;

FIG. 6 is a schematic view (including a state when a pellicle is peeledfrom a photomask) of a X-Y cross section of FIG. 4 ; and

FIG. 7 is a schematic side view when a conventional pellicle is attachedonto a photomask.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The pellicle frame according to the present invention is a pellicleframe in a frame shape, which has an upper end face on which a pelliclefilm is to be arranged and a lower end face to face a photomask.

As long as the pellicle frame has a frame shape, the shape correspondsto the shape of a photomask onto which a pellicle is to be attached. Ingeneral, the shape of a pellicle frame is a quadrilateral (rectangularor square) frame shape.

In addition, in a pellicle frame, there are a face on which a pelliclefilm is to be arranged (herein, referred to as an upper end face) and aface to face a photomask (herein, referred to as a lower end face) whenthe pellicle frame is attached onto the photomask.

In general, on the upper end face, a pellicle film is arranged with anadhesive agent or the like therebetween, and on the lower end face, apressure-sensitive adhesive or the like for attaching a pellicle onto aphotomask is provided, but cases of the present invention are notlimited to the above.

The material for a pellicle frame is not limited, and a known materialcan be used. In a pellicle frame for EUV, since there is a possibilityof being exposed to a high temperature, a material having a smallthermal expansion coefficient is preferred. For example, Si, SiO₂, SiN,quartz, invar, titanium, a titanium alloy, or the like can be mentioned.As a pellicle film for EUV, an ultrathin silicon film is expected to bepromising, and a silicon crystal which is the same material as that fora pellicle film is preferred. The silicon crystal may be either a singlecrystal or a polycrystal, and a silicon single crystal that is easy toobtain and is inexpensive is preferred.

The size of a pellicle frame is not particularly limited, however, sincethe height of a pellicle for EUV is limited to 2.5 mm or less, thethickness of a pellicle frame for EUV is smaller than the height and isless than 2.5 mm.

For example, in a case of forming a hole in a pellicle frame made of asilicon crystal, a margin of at least 0.5 mm is required around thehole. Therefore, in a case of forming a hole having a diameter of 1 mm,the thickness is required to be at least 2.0 mm. That is, the presentinvention is particularly useful for a pellicle frame that has athickness of less than 2.0 mm and is made of a silicon crystal.

In addition, the thickness of a pellicle frame for EUV is preferably 2.0mm or less, and more preferably 1.6 mm or less in consideration of thethickness of a pellicle film, a mask pressure-sensitive adhesive and thelike.

Further, in order to sufficiently exhibit a function as a pellicle, itis required to have a height of 1.5 mm or more. In this regard, thethickness of a pellicle frame for EUV is preferably 1.0 mm or more inconsideration of the thickness of a pellicle film, a maskpressure-sensitive adhesive and the like.

In the pellicle frame according to the present invention, a notched partis provided from the outer side face toward inner side face of the lowerend face. There are no restrictions on the location of the notched partand on the number of the notched parts, however, since the pellicleframe is used for holding a pellicle, it is preferred that the notchedpart is provided by one in each of two opposing sides at the minimum,that is, two or more notched parts in total are provided.

In addition, there are no restrictions also on the shape and size of thenotched part, however, if the height of the notched part is increased,the thickness of the pellicle frame on an upper side of the notched partis correspondingly reduced, and there is a possibility of breakage.Therefore, the height of the notched part is preferably 50% or less ofthe thickness of the pellicle frame, more preferably 30% or less, andfurthermore preferably 15% or less.

In a case of a pellicle frame made of a silicon crystal, it is preferredthat the thickness of the pellicle frame on an upper side of the notchedpart is set to be 0.7 mm or more.

The notched part may be formed up to the middle of the pellicle frame,or may be formed so as to communicate from an outer side face up to aninner side face. If the notched part is formed from an outer side faceup to an inner side face, the notched part can be used also as aventilation part.

In general, in a pellicle frame, a ventilation part for reducing thepressure difference between the inside and outside of the pellicle isarranged. In particular, in EUV lithography, in order to make the insideof an exposure device vacuum, a pellicle for EUV is required towithstand the pressure changes from the atmospheric pressure to thevacuum, and a pellicle frame for EUV is required to have a ventilationpart with a large area.

Conventionally, similarly as in the case of a jig hole, the ventilationpart is provided as a through hole on a side face of the pellicle frame.Therefore, there is a concern that the ventilation part may be brokenduring processing as in the case of a jig hole. In particular, in apellicle frame for EUV, a ventilation part with a large area isrequired, however, if the diameter of the through hole is set to belarger in order to make the ventilation part larger, the possibility ofbreakage is further increased. In addition, if the number of the throughholes is also set to be larger, the possibility of breakage is increasedsimilarly.

However, as long as the processing is for providing a notched part as inthe present invention, even at a place where a pellicle frame is thin,the place has a certain thickness, therefore, the processing can beeasily performed, and the possibility of breakage during processing canbe lowered.

Further, when a peeling jig is inserted into a notched part to peeledoff a pellicle, since a place (to come into contact with a peeling jigwhen the peeling jig is moved in an upper end face direction of apellicle frame), where force is most applied, has a thickness of largerthan that in the case of providing a hole in the vicinity of the centerof a side face, the breakage during peeling is also hardly generated.

In addition, in a case where a notched part is used as a ventilationpart, even if the height of the notched part is made smaller, so thatthe thickness of the pellicle frame is increased, by increasing thewidth, a large amount of ventilation can be realized.

In a case where a notched part is used as a ventilation part, the sizeof the part and the number of the parts are adjusted depending on thepressure change speed during the use of a pellicle. In a case of apellicle frame for EUV, the total area of the opening parts ispreferably at least 5 mm 2 or more, and more preferably 10 mm 2 or more.In addition, in the conventional excimer laser exposure, even if thetotal area was 1 mm 2 or less, it was sufficient.

For example, in a pellicle frame, both forms of a notched part formed upto the middle of the pellicle frame, and a notched part formed from anouter side face up to an inner side face may be provided. In thisregard, for example, the notched part formed up to the middle of thepellicle frame is used for peeling, and the notched part formed from anouter side face up to an inner side face is used for ventilation, theapplication may be separated as such.

Further, multiple notched parts to be provided in a pellicle frame mayhave different shapes and sizes. For example, as described above, in acase where the application of notched parts is separated, the optimalshape and size can be selected depending on the application.

In addition, a filter may be arranged in a notched part formed from anouter side face up to an inner side face. In a case where the notchedpart is used for peeling, it is preferred to arrange a filter on aninner side face of the pellicle frame so as to cover the notched part,or to arrange a filter inside the notched part. In a case where thenotched part is used only for ventilation, a filter may be arranged onan outer side face of the pellicle frame so as to cover the notchedpart.

In a case where a pressure-sensitive adhesive or the like is formed on alower end face of a pellicle frame, it is preferred to adjust the filtersize to the thickness of the pressure-sensitive adhesive.

The notched part can be used not only for peeling and ventilation butalso as a jig hole during handling. Since a larger force is not appliedto the jig hole for handling as compared with the force applied to a jighole for peeling, the jig hole for handling may be provided as usual inthe vicinity of the center of an outer side face of the pellicle frame.Further, as needed, other processing may be performed on an outer sideface or an inner side face within the range of not being broken duringprocessing.

In the pellicle according to the present invention, a pellicle film isarranged on an upper end face of the pellicle frame having the aboveconstitution with a pressure-sensitive adhesive or an adhesive agenttherebetween. The material for the pressure-sensitive adhesive or theadhesive agent is not limited, and a known material can be used. Ingeneral, the pressure-sensitive adhesive or the adhesive agent is formedso as to have a width equal to or smaller than the width of the pellicleframe over the entire circumferential direction of an end face of thepellicle frame.

In addition, there is no restriction on a material for a pellicle film,and as the material, a material having a high transmittance at awavelength of an exposure light source and a high light resistance ispreferred. For example, an ultrathin silicon film, a carbon film, or thelike is used for EUV exposure.

Further, on a lower end face of a pellicle frame, a pressure-sensitiveadhesive for the attachment onto a photomask is formed. Thepressure-sensitive adhesive is preferably arranged on a part other thanthe notched part on a lower end face of the pellicle frame.

As the above-described pressure-sensitive adhesive, a knownpressure-sensitive adhesive can be used, and an acrylicpressure-sensitive adhesive or a silicone-based pressure-sensitiveadhesive can be suitably used. A silicone-based pressure-sensitiveadhesive is preferred from the viewpoint of the heat resistance. Thepressure-sensitive adhesive may be processed into an arbitrary shape asneeded.

On a lower end face of the pressure-sensitive adhesive, a release layer(separator) for protecting the pressure-sensitive adhesive may beattached. There is no particular restriction on a material for therelease layer, and for example, polyethylene terephthalate (PET),polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinylether copolymer (PFA), polyethylene (PE), polycarbonate (PC), polyvinylchloride (PVC), polypropylene (PP), or the like can be used. Further, asneeded, a release agent such as a silicone-based release agent or afluorine-based release agent may be applied onto a surface of therelease layer.

In the present invention, by inserting a peeling jig into a notched partfrom a side face of a pellicle frame, and moving the peeling jig in anupper end face direction of the pellicle frame in this state, a pellicleis peeled off from a photomask onto which the pellicle has beenattached.

At this time, when the peeling jig is moved in an upper end facedirection of the pellicle frame, the peeling jig preferably has a flatplate shape if the place to come into contact with the peeling jig ofthe pellicle frame is flat. The peeling jig preferably has a shapecorresponding to the shape of a place to come into contact with thepeeling jig of the pellicle frame. In this way, the contact area betweenthe peeling jig and the upper side of the notched part is increased, sothat the breakage of the pellicle frame is hardly generated.

Herein, FIGS. 1A to 1C, 2A to 2C, and 3A to 3C show an example of apellicle frame 1 according to the present invention, and in eachdrawing, the reference sign 11 shows an inner side face of the pellicleframe, the reference sign 12 shows an outer side face of the pellicleframe, the reference sign 13 shows an upper end face of the pellicleframe, and the reference sign 14 shows a lower end face of the pellicleframe. The above-described pellicle frame 1 is provided with a notchedpart 2, and the reference sign 21 shows a width of the notched part, thereference sign 22 shows a depth of the notched part, and the referencesign 23 shows a height of the notched part. In addition, in FIGS. 2A to2C, the notched part on the long side is formed from an outer side faceto an inner side face, the notched part on the short side is formed upto the middle of the pellicle frame, and the notched part on the shortside has a height larger than the height of the notched part on the longside so that a peeling jig can be easily inserted. Further, FIG. 5 showsa pellicle 3, and a pellicle film 5 is bonded and stretched onto anupper end face of the pellicle frame 1 by an adhesive agent 6.Furthermore, the pellicle 3 is peelably bonded to a photomask 7 by apressure-sensitive adhesive 4 to protect a pattern surface on thephotomask 7. Moreover, FIG. 6 shows a state in which a peeling jig 8 isinserted through the notched part 2 of the pellicle frame 1 when peelingoff the pellicle from the photomask.

EXAMPLES

Hereinafter, the present invention is specifically described withreference to Examples and Comparative Examples, however, the presentinvention is not limited to the following Examples.

Example 1

A pellicle frame (with an outer size of 150 mm×118 mm×1.5 mm, and aframe width of 4 mm) made of a Si single crystal was prepared.

As shown in Example 1, a notched part with a width of 70 mm, a height of0.2 mm, and a depth of 4 mm was provided on a lower end face at thecenter of each side of the pellicle frame. The notched part was formedfrom an outer side face up to an inner side face. In addition, thethickness on the upper side of the notched part was 1.3 mm, and theprocessing was performed without breakage.

The pellicle frame was cleaned, and a silicone pressure-sensitiveadhesive (X-40-3264 manufactured by Shin-Etsu Chemical Co., Ltd.) wasapplied over the entire circumference of an upper end face of the frame.Further, a silicone-based pressure-sensitive adhesive (X-40-3264manufactured by Shin-Etsu Chemical Co., Ltd.) was applied as a maskpressure-sensitive adhesive also on a part other than the notched parton a lower end face of the frame.

After that, the pellicle frame was heated at 90° C. for 12 hours to curethe pressure-sensitive adhesive on the upper and lower end faces.Subsequently, an ultrathin silicon film as a pellicle film was pressbonded to the pressure-sensitive adhesive formed on the upper end faceof the frame, and a pellicle was completed.

The pellicle was attached onto a quartz mask with a size of 150 mm×150mm as a substitute for a photomask, and then a flat plate-shaped part ofa peeling jig was inserted into the notched part, and by moving thepeeling jig in an upper end face direction of the pellicle frame at aspeed of 0.1 mm/s, the pellicle was peeled off from the photomask. Evenwhen the pellicle was peeled off, the pellicle frame was not broken.

Example 2

A pellicle frame (with an outer size of 150 mm×118 mm×1.5 mm, and aframe width of 4 mm) made of a Si single crystal was prepared.

As shown in Example 2, on a lower end face of the long side of thepellicle frame, two notched parts each with a width of 30 mm, a heightof 0.2 mm and a depth of 4 mm were provided at two places with a spaceof 30 mm. On a lower end face of the short side, two notched parts eachwith a width of 20 mm, a height of 0.2 mm and a depth of 4 mm wereprovided at two places with a space of 20 mm. The notched part is formedfrom an outer side face up to an inner side face. In addition, thethickness on the upper side of the notched part was 1.3 mm, and theprocessing was performed without breakage.

The pellicle frame was cleaned, and a silicone-based pressure-sensitiveadhesive (X-40-3264 manufactured by Shin-Etsu Chemical Co., Ltd.) wasapplied over the entire circumference of an upper end face of the frame.In addition, an acrylic pressure-sensitive adhesive (SK-DYNE 1495manufactured by Soken Chemical & Engineering Co., Ltd.) was applied as amask pressure-sensitive adhesive also on a part other than the notchedpart on a lower end face of the frame.

After that, the pellicle frame was heated at 90° C. for 12 hours to curethe pressure-sensitive adhesive on the upper and lower end faces.Subsequently, an ultrathin silicon film as a pellicle film was pressbonded to the pressure-sensitive adhesive formed on the upper end faceof the frame, and a pellicle was completed.

The pellicle was attached onto a quartz mask with a size of 150 mm×150mm as a substitute for a photomask, and then a flat plate-shaped part ofa peeling jig was inserted into the notched part, and by moving thepeeling jig in an upper end face direction of the pellicle frame at aspeed of 0.1 mm/s, the pellicle was peeled off from the photomask. Evenwhen the pellicle was peeled off, the pellicle frame was not broken.

Comparative Example 1

A pellicle frame (with an outer size of 150 mm×118 mm×1.5 mm, and aframe width of 4 mm) made of a Si single crystal was prepared.

On an outer side face of the long side of the pellicle frame, two jigholes each having a diameter of 1 mm and a depth of 1 mm were tried tobe provided at two places each with a distance of 45 mm away from thecenter of the side in the corner direction, however, breakage occurredduring the processing.

Comparative Example 2

A pellicle frame (with an outer size of 150 mm×118 mm×1.5 mm, and aframe width of 4 mm) made of a Si single crystal was prepared.

On an outer side face of the long side of the pellicle frame, two jigholes each having a diameter of 0.5 mm and a depth of 1 mm were providedat two places each with a distance of 45 mm away from the center of theside in the corner direction. The thickness on the upper side of the jighole was 0.5 mm, and the processing was performed without breakage.

The pellicle frame was cleaned, and a silicone pressure-sensitiveadhesive (X-40-3264 manufactured by Shin-Etsu Chemical Co., Ltd.) wasapplied over the entire circumference of an upper end face of the frame.In addition, a silicone pressure-sensitive adhesive (X-40-3264manufactured by Shin-Etsu Chemical Co., Ltd.) was applied as a maskpressure-sensitive adhesive also on a part other than the notched parton a lower end face of the frame.

After that, the pellicle frame was heated at 90° C. for 12 hours to curethe pressure-sensitive adhesive on the upper and lower end faces.Subsequently, an ultrathin silicon film as a pellicle film was pressbonded to the pressure-sensitive adhesive formed on the upper end faceof the frame, and a pellicle was completed.

The pellicle was attached onto a quartz mask with a size of 150 mm×150mm as a substitute for a photomask, and then a cylindrical-shaped partof a peeling jig was inserted into the jig hole, and the pellicle wastried to be peeled off from the photomask by moving the peeling jig inan upper end face direction of the pellicle frame at a speed of 0.1mm/s. However, a peripheral part of the jig hole was broken, and thepellicle was not able to be peeled off.

Japanese Patent Application No. 2017-196982 is incorporated herein byreference.

Although some preferred embodiments have been described, manymodifications and variations may be made thereto in light of the aboveteachings. It is therefore to be understood that the invention may bepracticed otherwise than as specifically described without departingfrom the scope of the appended claims.

1. A pellicle frame having two end faces in a quadrilateral frame shape,having a recessed portion provided so that the recessed portion extendsfrom one of said two end faces toward another of said two end faces, andhaving a thickness of less than 2.5 mm, wherein the length on the lengthdirection of the side of the recessed portion is longer than the heightof the recessed portion.
 2. The pellicle frame of claim 1, wherein therecessed portion is an element of a ventilation portion.
 3. The pellicleframe of claim 2, wherein the ventilation portion has opening parts andthe total area of the opening parts is an area applicable to EUVlithography.
 4. The pellicle frame of claim 2, wherein the ventilationportion has opening parts and the total area of the opening parts is aresolvable area for resolving the pressure changes between theatmospheric pressure and the vacuum.
 5. The pellicle frame of claim 2,wherein the ventilation portion has opening parts and the total area ofthe opening parts is at least 40 mm².
 6. The pellicle frame of claim 1,wherein the height of the recessed portion is 30% or less of thethickness of the pellicle frame.
 7. The pellicle frame of claim 1,wherein the pellicle frame has two side faces and the recessed portionextends from one of said two side faces toward another of said two sidefaces.
 8. The pellicle frame of claim 1, wherein the pellicle frame hastwo side faces and the recessed portion extends from one of said twoside faces up to another of said two side faces.
 9. A pellicle framehaving two end faces in a quadrilateral frame shape, having a pluralityof recessed portions provided so that the recessed portions extend fromone of said two end faces toward another of said two end faces, whereinthe lengths on the length directions of the sides of the plurality ofrecessed portions are longer than the height of the recessed portion,and wherein at least one of the plurality of recessed portions is anelement of a ventilation portion.
 10. The pellicle frame of claim 9,wherein the thickness of the pellicle frame is less than 2.5 mm.
 11. Thepellicle frame of claim 9, wherein the ventilation portion has openingparts and the total area of the opening parts is an area applicable toEUV lithography.
 12. The pellicle frame of claim 9, wherein theventilation portion has opening parts and the total area of the openingparts is a resolvable area for resolving the pressure changes betweenthe atmospheric pressure and the vacuum.
 13. The pellicle frame of claim9, wherein the ventilation portion has opening parts and the total areaof the opening parts is at least 40 mm².
 14. The pellicle frame of claim9, wherein the height of the recessed portion is 30% or less of thethickness of the pellicle frame.
 15. The pellicle frame of claim 9,wherein the pellicle frame has two side faces and the recessed portionextends from one of said two side faces toward another of said two sidefaces.
 16. The pellicle frame of claim 9, wherein the pellicle frame hastwo side faces and the recessed portion extends from one of said twoside faces up to another of said two side faces.
 17. A pellicle,comprising: the pellicle frame of claim 1 as an element.
 18. A pellicle,comprising: the pellicle frame of claim 9 as an element.
 19. A pellicle,comprising: the pellicle frame having a recessed portion provided sothat the recessed portion extends from one of two end faces towardanother of said two end faces, wherein the recessed portion has a space,and the space is maintained as the space so that the space functions asa ventilation portion in using the pellicle.
 20. The pellicle frame ofclaim 19, wherein the thickness of the pellicle frame is less than 2.5mm.
 21. The pellicle frame of claim 19, wherein the ventilation portionhas opening parts and the total area of the opening parts is an areaapplicable to EUV lithography.
 22. The pellicle frame of claim 19,wherein the ventilation portion has opening parts and the total area ofthe opening parts is a resolvable area for resolving the pressurechanges between the atmospheric pressure and the vacuum.
 23. Thepellicle frame of claim 19, wherein the ventilation portion has openingparts and the total area of the opening parts is at least 40 mm². 24.The pellicle frame of claim 19, wherein the height of the recessedportion is 30% or less of the thickness of the pellicle frame.
 25. Thepellicle frame of claim 19, wherein the pellicle frame has two sidefaces and the recessed portion extends from one of said two side facestoward another of said two side faces.
 26. The pellicle frame of claim19, wherein the pellicle frame has two side faces and the recessedportion extends from one of said two side faces up to another of saidtwo side faces.
 27. An exposure method, wherein the exposure isperformed by using the pellicle of claim
 17. 28. An exposure method,wherein the exposure is performed by using the pellicle of claim
 18. 29.An exposure method, wherein the exposure is performed by using thepellicle of claim
 19. 30. A manufacturing method of a semiconductordevice, comprising a step of forming a pattern by irradiating asemiconductor wafer with an exposure, wherein the exposure is performedby using the pellicle of claim
 17. 31. A manufacturing method of asemiconductor device, comprising a step of forming a pattern byirradiating a semiconductor wafer with an exposure, wherein the exposureis performed by using the pellicle of claim
 18. 32. A manufacturingmethod of a semiconductor device, comprising a step of forming a patternby irradiating a semiconductor wafer with an exposure, wherein theexposure is performed by using the pellicle of claim 19.